论文部分内容阅读
利用裂纹面分离及SEM和EDS研究了L360MCS钢焊接热影响区(HAZ)在湿H_2S环境中的应力导向氢致开裂(SOHIC)行为.结果表明:应力导向氢致开裂裂纹由轴向和纵向两种裂纹组成,先形成轴向裂纹,后形成纵向裂纹,两种裂纹均独立形核.裂纹带有明显的阶梯状氢致开裂特征,裂纹面呈现准解理型断口形貌.拉应力在裂纹形核和扩展方面起主要作用,拉应力不仅增加了拉伸区的过饱和氢浓度,而且直接推动纵向裂纹的扩展.轴向裂纹在MnS和CaS夹杂以及析出相处形核,以氢压为主要的裂纹扩展动力.而纵向裂纹则主要在析出相处萌生,裂纹扩展受拉应力和氢压双重控制,拉应力为主导.
The stress-induced hydrogen induced cracking (SOHIC) behavior of HAZ in wet H_2S environment was investigated by means of crack surface separation and SEM and EDS. The results show that stress-induced hydrogen induced cracking is composed of axial and longitudinal The cracks are obviously formed by the step-like hydrogen induced cracking, and the crack surface presents the quasi-cleavage fracture surface. The tensile stress in the crack Nucleation and expansion. Tensile stress not only increases the supersaturated hydrogen concentration in the stretching zone, but also directly promotes the extension of the longitudinal cracks. Axial cracks are nucleated and mixed with MnS and CaS, While the longitudinal cracks mainly initiate in the phase of precipitation, and the crack propagation is controlled by both tensile stress and hydrogen pressure, and the tensile stress is dominant.